1. Field of the Invention
The present invention relates to an apparatus for guiding a supply reel and a take-up reel of a magnetic recording/reproducing apparatus, and more particularly to a reel guide apparatus of a magnetic recorder/reproducer, wherein a supply reel and a take-up reel installed on a slider are accurately and stably placed on a lower chassis while generating accurate reel pulses.
2. Description of the Prior Art
Generally, magnetic recording/reproducing devices, such as a video tape recorder, are commonly in use today to the extent that they may be considered staple commodities. The most common household magnetic recording/reproducing devices utilize half inch tape cassettes and the standard VHS system and include a cassette holder which holds the tape cassette and driving members which pull the cassette holder into the interior of a main body thereof to seat the cassette holder on a main deck. In addition, the standard VHS device includes a unit which loads and unloads magnetic tape from the tape cassette onto and from a rotary drum installed on the main drum, and units for allowing the magnetic tape to travel along a predetermined path.
When the cassette is in the cassette holder, the insertion of the cassette holder is monitored to seat the tape cassette on the main deck. The magnetic tape is loaded by means of a pair of pole bases onto the rotary drum for recording signals on the magnetic tape or reproducing the signals previously recorded on the magnetic tape.
More recently, camcorders have been developed for use with 8 mm tape cassettes in order to provide video camera magnetic recorder/reproducer functions in a convenient and light weight package. As a result, many products are currently available that use an 8 mm tape cassette.
One major factor determining the weight and size of such devices is the size of the deck of the recording/reproducing device. As a result of research and development efforts, the inventors of the present invention previously developed a magnetic recording/reproducing device with a reduced size deck and simplified components. The latter device is described in Korean Patent Application No. 93-5016. In the latter device, a tape cassette is inserted into a cassette holder having a rotary drum, and the cassette holder is then pressed closed to fully load the magnetic tape. The rotary drum is completely held within the internal space of the tape cassette while the loading operation of the tape cassette is completed. This permits the deck to be very small. This apparatus will be briefly described below.
FIG. 1 is a side view showing the aforementioned magnetic recording/reproducing apparatus. An eject lever 10 is coupled to a pair of brackets 11 via a pair of lever arms 10a, extending from a rear portion of the eject lever 10, by means of a shaft 11a. The pair of brackets 11 are erected in the interior of a main body (not shown) of the apparatus. The eject lever 10 pivots about the shaft 11a to enable the opening/closing operation upward and downward. When a locking pin 10b, located on the front of the eject lever 10, is released, the eject lever pivots upward to expose it on the outside of the main body a predetermined angular amount. This permits one to insert or remove a tape cassette 20.
Also, a pair of elastic members 12, attached to the inner surface of the eject lever 10, press on the upper surface of the tape cassette 20 to hold the cassette tightly in the lever 10 when the pressing operation of the eject lever is completed. A pin 10c, provided in one side of the arm 10a of the eject lever 10, fits into an elongated hole 30b of a bracket 30a, which is erected on the side of an upper chassis 30. This construction causes the upper chassis 30 to move vertically upward and downward when the eject lever 10 swings upward and downward, respectively.
A cassette holder 40 for receiving the tape cassette 20, a slider 50 for forwardly and backwardly moving the cassette holder 40 in the horizontal direction, and the upper chassis 30 mounted with a rotary drum 31 for initially loading the magnetic tape during the horizontal movement of the slider 50 are provided inside of the eject lever 10. One end of the cassette holder 40 is connected to one end of the slider 50 by means of a shaft 40a. A first link 41, formed around the center of the slider 50, is connected to a second link 42, which by means of a pin 43 slides along an elongated hole 50b in a bracket 50a formed on the side of the slider 50. Therefore, the cassette holder 40 can swing around the shaft 40a by a predetermined angle to permit insertion and ejection of the tape cassette 20.
A lid-open member 44, which swings upward and downward about a shaft 44a at one end thereof, is installed on one side of the cassette holder 40. A pin 40b, projecting from the side of the cassette holder 40, fits within and is guided along an elongated hole 44b formed in approximately the center of the lid-open member 44. The center of the lid-open member 44 is coupled with the slider 50 by means of a third link 45 inclined at a predetermined angle. The second link 42 and the third link 45 are connected by an elastic member 46. Accordingly, during seating of the cassette holder 40 on the slider 50, the lid-open member 44 swings about the shaft 44 to open a lid 20a of the tape cassette 20.
A pair of reel bases 51 and 52, which support reels 53 and 54, are mounted on the slider 50. The reels 53 and 54 receive the hubs of the tape cassette 20. The forward and backward movement of the slider 50 in the horizontal direction is executed by means of a slider transportation apparatus (not shown) installed on the upper chassis.
A lower chassis 60, mounted with travelling elements for driving the magnetic tape within the tape cassette 20, is installed below the lower portion of the upper chassis 30. The upper chassis is moved up and down relative to the lower chassis 60 by means of a Scott Russel link mechanism principle. A pair of intersecting fourth and fifth links 60a and 60b are provided on the sides of the upper chassis and the lower chassis 60. The links include pins 60c projecting on the respective ends thereof for connecting the links to the upper and lower chassis. An elastic member 61 hooks respective links 60a and 60b together to result in the upper chassis being elastically moved in the up and down directions.
When the cassette holder 40a is closed after the tape cassette 20 is inserted in cassette holder 40, it rotates about the shaft 40a to seat on the slider 50. At this time, the hubs of the tape cassette 20 are guided by the reels 53, 54, and, simultaneously, the lid-open member 44 on the side of the cassette holder 40 rotates clockwise about the shaft 44a to open the lid 20a of the tape cassette 20. If the cassette holder 40 is pushed toward the upper chassis 30, the slider transportation apparatus mounted on the upper chassis 30 horizontally transports the slider 50 toward the upper chassis 30 to enable the loading operation of the magnetic tape with respect to the rotary drum 31.
FIG. 2 shows the state of the device after the first stage of the loading process. Thereafter, when the eject lever 10 is pressed down by a user, it pivots about the shaft 11a. The pin 10c on lever 10 presses down on the chassis 30 via elongated opening 30b, thereby causing the chassis 30 to move downward via the elastic member 61 onto the lower chassis 60. As the lever 10 reaches its lowest point the locking pin 10b at the end of lever 10 is hooked and locked by the locking device 70 on the lower chassis 60.
Since the reels 53 and 54 move downward to be seated on the lower chassis 60, the reels must be accurately guided to the lower chassis 60, and the tape cassette 20 should not become loose within the holder; i.e., the tape cassette should not float within the tape cassette holder. Moreover, overall units for horizontally placing the reels at a predetermined height about the lower chassis and generating reel pulses for indicating the remaining amount of magnetic tape are not provided.